Year Percent 1950 9.26359 1955 8.44535 1960 7.7299 1965 7.7525 1970 7.81247 1975 7.94596 1980 7.95698 1985 8.28513 1990 9.50385 1995 9.78189 2000 10.38927 2005 9.19386 2010 10.03337 2015 12.41706 2020 14.87848 2025 18.01589 2030 20.9346 2035 23.64695 2040 25.97036 2045 27.89267 2050 28.80602 2055 29.00428 2060 28.40367 2065 27.83595 2070 28.35515 2075 30.10482 2080 31.57357 2085 32.45828 2090 33.1187 2095 33.85616 2100 34.71466